Monoacylglycerol Contents Research Articles

Characterization of Palm Fatty Acid Distillate, Diacylglycerol Regioisomers, and Esterification Products Using High-Performance Size Exclusion Chromatography.

High-performance size exclusion chromatography (HPSEC) equipped with an evaporative light scattering detector (ELSD) was utilized for characterization of palm fatty acid distillate (PFAD) and its esterified products, with a particular focus on lipid profiles and diacylglycerol (DAG) regioisomers. The separation of triacylglycerol (TAG), DAG, monoacylglycerol (MAG), and free fatty acid (FFA) was achieved through a single 100-Å Phenogel column, coupled with a 2-cm C18 guard, utilizing toluene/acetic acid (100:0.25, v/v) as the mobile phase. This separation was based on size sieving principles and the interactions between the hydroxyl group(s) and the Phenogel matrix. The limit of detection (LOD) and limit of quantification (LOQ) for the esterified PFAD products analyzed by this method fell within the range of 4.8-5.5 μg/mL and 14.7-16.7 μg/mL, respectively. Additionally, the same column, paired with a 2-cm silica guard and a mobile phase comprised of toluene/isooctane/acetic acid (35:65:0.15, v/v/v), was used for the characterization of DAG regioisomers within the esterified PFAD. LODs and LOQs for sn-1,3-DAG and sn- 1,2-DAG were determined to be 39.2 and 118.7 μg/mL, and 32.8 and 99.5 μg/mL, respectively. Investigation of esterified PFAD products prepared using 4% H2SO4 at 120°C. After 2 h, the analysis revealed the highest MAG content at 31.85%, accompanied by 51.54% DAG, 2.35% TAG, and a residual 14.27% FFA. Notably, as the reaction time extended, the MAG content decreased, while both DAG and TAG levels exhibited an increasing trend. Further examination of DAG regioisomers during PFAD esterification, under varying catalyst concentrations (2-10%) and reaction temperatures (80-140°C), demonstrated a significant increase in the percentage of sn-1,3-DAG, inversely correlated with the reduction in FFA from 2% H 2 SO 4 and 80°C onwards. Remarkably, the percentage of sn-1,2-DAG remained relatively stable regardless of changes in catalyst concentrations or temperatures, confirming its susceptibility to isomerization into the thermodynamically more stable sn-1,3-DAG form. This study provides valuable insights into the composition and behavior of esterified PFAD products.

Fourier transform infrared spectroscopy and chemometrics for chemical property prediction of chemically interesterified lipids with butterfat and vegetable oils during storage

The storage stability of structured lipids has a great importance for food industry and should be defined clearly. The aim of the study is to manufacture structured lipids by chemical interesterification of butterfat with different vegetable oils, to determine some chemical properties of interesterified lipids throughout storage and to predict free fatty acid, peroxide value, malondialdehyde and mono-di-triacylglycerol contents of these lipids by using middle infrared spectroscopy (FT-MIR). Prediction models were constructed by using partial least square (PLS) regression with an external cross-validation. The PLS model for TAG with FT-MIR data showed an excellent predictive potential with higher R2cal=0.98, R2cv=0.99 and lower RMSE values. The model for monoacylglycerol content (MAG) showed a good predictive ability with higher R2cal=0.88, R2cv=0.90 and lower RMSE values. The PLS model constructed with FT-IR spectra for diacylglycerol (DAG) content have good capability of prediction due to higher R2 and lower RMSE values. For the prediction of malondialdehyde (MAD) of interesterified lipids by FT-MIR spectra, regression coefficient of calibration set was found as 0.84. For the prediction of peroxide value (PV) of interesterified lipids with FT-MIR spectra, R2CV=0.76 and RMSEC=1.52 and RMSECV=1.15. Infrared spectroscopy technique could be used for analyzing the chemical changes of fats during storage and also suggests a rapid and non-destructive techniques as good alternatives to the traditional analytical methods.

A comprehensive study on physicochemical properties, bioactive compounds, and emulsified lipid digestion characteristics of Idesia polycarpa var. Vestita Diels fruits oil

Idesia polycarpa var. vestita Diels fruits oil (IPO) has the potential to broaden the availability of healthy vegetable oil and relieve pressure on the edible oil supply. In this study, we compared the physicochemical, bioactivity, and digestive properties of IPO, olive oil (OO), and soybean oil (SO) to comprehensively evaluate the edible potential of IPO. The results revealed no significant differences in relative density or refractive index among the three oils. IPO was rich in β-sitosterol (366.74 mg/100 g), β-tocopherol (8.42 mg/100 g), and α-tocopherol (37.10 mg/100 g). The digestive properties of IPO emulsion were investigated for the first time using in vitro simulated digestion. The IPO emulsion stood out regarding its free fatty acid release (88.03 %). Finally, the IPO emulsion released mainly unsaturated fatty acids and had a higher monoacylglycerol content. This study provides new insights into IPO as a high-quality edible vegetable oil.

Angiopoietin-like 4 governs diurnal lipoprotein lipase activity in brown adipose tissue

ObjectiveBrown adipose tissue (BAT) burns fatty acids (FAs) to produce heat, and shows diurnal oscillation in glucose and triglyceride (TG)-derived FA-uptake, peaking around wakening. Here we aimed to gain insight in the diurnal regulation of metabolic BAT activity. MethodsRNA-sequencing, chromatin immunoprecipitation (ChIP)-sequencing, and lipidomics analyses were performed on BAT samples of wild type C57BL/6J mice collected at 3-hour intervals throughout the day. Knockout and overexpression models were used to study causal relationships in diurnal lipid handling by BAT. ResultsWe identified pronounced enrichment of oscillating genes involved in extracellular lipolysis in BAT, accompanied by oscillations of FA and monoacylglycerol content. This coincided with peak lipoprotein lipase (Lpl) expression, and was predicted to be driven by peroxisome proliferator-activated receptor gamma (PPARγ) activity. ChIP-sequencing for PPARγ confirmed oscillation in binding of PPARγ to Lpl. Of the known LPL-modulators, angiopoietin-like 4 (Angptl4) showed the largest diurnal amplitude opposite to Lpl, and both Angptl4 knockout and overexpression attenuated oscillations of LPL activity and TG-derived FA-uptake by BAT. ConclusionsOur findings highlight involvement of PPARγ and a crucial role of ANGPTL4 in mediating the diurnal oscillation of TG-derived FA-uptake by BAT, and imply that time of day is essential when targeting LPL activity in BAT to improve metabolic health.

Enhanced environment friendly surfactant production by the glycerolysis of castor oil using amino acid ionic liquid as a catalyst

Monoacylglycerol (MAG) is one kind of the oil-based nonionic surfactant, which has the excellent emulsifying property and biodegradability. In this work, several novel and green amino acid ionic liquids (AAILs) were developed as eco-friendly catalysts to promote the glycerolysis of castor (Ricinus communis L.) oil for the green castor oil-based MAG production. Nine AAILs, consisting of an amino acid anion (arginine (Arg), lysine (Lys) and histidine (His)), and an organic hydroxide cation (choline hydroxide (ChOH), tetramethylhydroxide ammonium (TMAOH) and tetrabutylammonium hydroxide (TBAOH)), were synthesized by a simple and green chemical route and used as catalysts to catalyze the glycerolysis of castor oil. Effects of the structural composition of AAILs, reaction time (0-120 min), castor oil and glycerol molar ratio (1:2-1:10), AAIL load (4-12%), and temperature (60-120℃) on the glycerolysis were evaluated and optimized by Box–Behnken methodology. Particularly, the effect of free fatty acid content in castor oil (0-25%) was also investigated to analyze the fatty acid tolerance of AAILs. Among the tested AAILs, [Ch][Arg], [TMA][Arg], and [TBA][Arg] showed the outstanding catalysis performance. Especially, [Ch][Arg] as reaction catalyst for the glycerolysis of castor oil exhibited the best catalysis activity, and high selectivity for MAG formation. The maximum TAG conversion (99.6 ± 0.4%) and MAG content (83.3 ± 1.6%) were obtained under the optimized conditions: 93.7℃, 60.7 min, [Ch][Arg] load 12.3%, and substrate molar ratio 1:6.4. Besides, [Ch][Arg] still had 80% catalytic activity when the free fatty acid content was 20% in castor oil. Kinetic analysis of the glycrolysis was also evaluated. Accordingly, activation energy (Ea) and average reaction order (a) of the glycerolysis were obtained as 59.7 kJ/mol and 1.69, respectively.

An Effective Strategy for the Production of Lauric Acid-Enriched Monoacylglycerol via Enzymatic Glycerolysis from Black Soldier Fly (Hermetia illucens) Larvae (BSFL) Oil.

Here, we developed an efficient strategy for the production of lauric acid-enriched monoacylglycerol (MAG) via enzymatic glycerolysis using black soldier fly (Hermetia illucens) larvae (BSFL) oil. The effects of the substrate molar ratio, reaction temperature, type of immobilized lipase, and organic solvent on the MAG content and conversion degree of BSFL oil were optimized. The maximum substrate conversion rate (97.88%) and MAG content (70.84%) were obtained in a tert-butanol system at 50 °C with a glycerol/BSFL oil molar ratio of 4:1 by using immobilized MAS1 lipase as a catalyst. The MAG content in the purified product reached 97.7%, with lauric acid accounting for 50.2%. Improved oxidation stability was observed after glycerolysis. Overall, this study provides a new strategy for the preparation of lauric acid-enriched MAG from BSFL oil.

Molecular phenomics of a high-calorie diet-induced porcine model of prepubertal obesity

As obesity incidence is alarmingly rising among young individuals, we aimed to characterize an experimental model of this situation, considering the similarity between human and porcine physiology. For this reason, we fed prepubertal (63 days old) Duroc breed females (n=21) either with a standard growth diet (3800 kcal/day) or one with a high-calorie content (5200 kcal/day) during 70 days. Computerized tomography, mass-spectrometry-based metabolomics and lipidomics, as well as peripheral blood mononuclear cell transcriptomics, were applied to define traits linked to high-calorie intake. Samples from a human cohort confirmed potential lipidomic markers. Compared to those fed a standard growth diet, pigs fed a high-calorie diet showed an increased weight gain (13%), much higher adiposity (53%), hypertriacylglyceridemia and hypercholesterolemia in parallel to insulin resistance. This diet induced marked changes in the circulating lipidome, particularly in phosphatidylethanolamine-type molecules. Also, circulating specific diacylglycerol and monoacylglycerol contents correlated with visceral fat and intrahepatic triacylglycerol concentrations. Specific lipids associated with obesity in swine (mainly belonging to glycerophospholipid, triacylglyceride and sterol classes) were also linked with obesity traits in the human cohort, reinforcing the usefulness of the chosen approach. Interestingly, no overt inflammation in plasma or adipose tissue was evident in this model. The presented model is useful as a preclinical surrogate of prepubertal obesity in order to ascertain the pathophysiology interactions between energy intake and obesity development.

Programming of hepatic lipid metabolism in a rat model of postnatal nicotine exposure – Sex-related differences

Maternal nicotine exposure during lactation induces liver damage in adult male rats. However, the mechanism in males is unknown and females have not been tested. Here, we determined the liver lipid composition and lipogenic enzymes in male and female offspring at two ages in a model of postnatal nicotine exposure. Osmotic minipumps were implanted in lactating Wistar rat dams at postnatal day (PND) 2 to release 6 mg/kg/day of nicotine (NIC group) or saline (CON group) for 14 days. Offspring received a standard diet from weaning until euthanasia at PND120 (1 pup/litter/sex) or PND180 (2 pups/litter/sex). At PND120, NIC males showed lower plasma triglycerides (TG), steatosis degree 1, higher hepatic cholesterol (CHOL) ester, free fatty acids, monoacylglycerol content as well as acetyl-coa carboxylase-1 (ACC-1) and fatty acid synthase (FAS) protein expression in the liver compared to CON males. At this age, NIC females had preserved hepatocytes architecture, higher plasma CHOL, higher CHOL ester and lower total CHOL content in the liver compared to CON females. At PND180, NIC males showed steatosis degrees 1 and 2, higher TG, lower free fatty acids and total CHOL content in the liver and an increase in ACC-1 hepatic protein expression. NIC females had higher plasma TG and CHOL levels, no change in hepatic morphology, lower CHOL ester and free fatty acids in the liver, which also showed higher total ACC-1 and FAS protein expression. Maternal nicotine exposure induces long-term liver dysfunction, with an alteration in hepatic cytoarchitecture that was aggravated with age in males. Concerning females, despite unchanged hepatic cytoarchitecture, lipid metabolism was compromised, which deserves further attention.

Optimization of the composition of fat systems of new generation

Fats are an integral part of human nutrition. The increased content of trans-isomers in their composition causes a number of cardiovascular diseases and metabolic disorders. A promising approach to solving the problem of minimizing the content of trans- isomers of fatty acid in the composition of food products is the creation of a new generation of fat systems – the oleogel, which is the subject of the presented research. As the dispersion medium of the oleogel, high-oleic sunflower oil is used, in contrast to the oil of traditional varieties, it is possible to obtain systems with enhanced oxidation resistance. The dispersed phase of these fat systems is beeswax, tripalmitin and monoacylglycerols. The choice of a complex of these components is based on their properties to create in oleogels a three-dimensional structure with desired thermomechanical characteristics. At present, there is not enough information about the dependence of the main characteristics of the oleogel on the ratio of ingredients of dispersed phase. In particular, one of the most problematic places in the oleogel technology is its thermal stability, which significantly affects the parameters of production, transportation, as well as storage conditions and periods. To solve this problem, the methodology of the response surface is used in the work. The determination of the unknown values of the parameter vector is carried out by applying regression analysis algorithms. The minimization of the deviation functional is performed by finding the appropriate combinations of experimental predictor series. As a result of research, a mathematical model is developed, which allows, based on data on the component composition of the oleogel, to predict its thermal stability. Reasonably rational mass fractions of the components of the dispersed phase of the oleogel: the content of beeswax is 3.27 wt. %; content of tripalmitin is 3.07 wt. % and the content of monoacylglycerol is 4.70 wt. %, at which the maximum value of the response function is reached. The results will serve as a scientific basis for the development of technological parameters of the industrial production of fat systems of the new generation, the conditions and terms of their storage and transportation.

Prediction of oxidative stability in bulk oils using dielectric constant changes

The effects of amphiphilic compounds on the dielectric constant of bulk oils were determined and the utility of the dielectric constant as a reliable parameter for predicting the oxidative stability of edible oils was evaluated. As the content of monoacylglycerols (MAGs), lecithin, and moisture increased, the dielectric constant of modified corn oil increased at different rates, whereas the addition of free fatty acids, including oleic and linoleic acid, decreased the dielectric constant of modified corn oil. Unoxidized fresh bulk oils showed a wide range of dielectric constants, from 8 for canola oils to 33 for flaxseed oils. The dielectric constant showed a strong correlation with the percentage of unsaturated fatty acids in the bulk oils. Oils with low oxidative stability had a high dielectric constant. Overall, the dielectric constant of bulk oils is strongly correlated with the content of amphiphilic compounds, moisture content, and degree of unsaturation of fatty acids.

Influence of acylglycerol emulsifier structure and composition on the function of shortening in layer cake

The effect of the structure and composition of acylglycerol emulsifiers on the functionality of a palm-based shortening and quality of layer cake was investigated. The emulsifiers evaluated were distilled monoacylglycerol (DMG) and four acylglycerols (40% monoacylglycerol content) of octanoic acid (8:0), palmitic acid (16:0), stearic acid (18:0), and linoleic acid (18:2), designated as GMOct40, GMP40, GMS40, and GML40, respectively. The addition of GMP40 and GMS40 led to shortening with a higher solid fat content, finer crystals, and higher proportion of β’ form. These changes enhanced shortening’s function in aiding air incorporation and retention in cake batter, which improved the cake’s volume and crumb structure. However, the high monoacylglycerol content in DMG did not improve the properties of shortening and cake as compared to GMP40. In contrast, GML40 and GMOct40 had adverse effects on the functionality of shortening, which generated cakes with inferior crumb structure.

Modified Gas Chromatographic Method to Determine Monoacylglycerol and Diacylglycerol Contents in Edible Fats and Oils

Monoacylglycerol (MAG) and diacylglycerol (DAG) are minor components of edible fats and oils, and they relate to the quality of these foods. The AOCS official method Cd 11b-91 has been used to determine MAG and DAG contents in fats and oils. There are, however, difficulties in the determination of MAG and DAG using this analytical procedure. Therefore, we improved this method by modifying the trimethylsilyl derivatization procedure and replacing the internal standard (IS) material. In our modified method, TMS-HT (mixture of hexamethyldisilazane and trimethylchlorosilane) was used for derivatization of MAG and DAG, which was followed by liquid-liquid extraction with water and n-hexane solution containing the IS, tricaprin. Using the modified method, we demonstrated superior repeatability in comparison with that of the AOCS method by reducing procedural difficulties. The relative standard deviation of distearin peak areas was 1.8% or 2.9% in the modified method, while it was 5.6% in the AOCS method. In addition, capillary columns, such as DB-1ht and DB-5ht could be used in this method.

Continuous Packed-Bed Biodiesel Polishing Using Particulate Materials

This work reports experimental data on dry-washing of biodiesel produced by enzyme-catalyzed reaction using ion exchange resins, a commercial immobilized enzyme, and a magnesium silicate adsorbent. Experiments were carried out in continuous-mode packed-bed column, varying operating temperature and pressure, and residence time toward reaching the current specifications of the biodiesel samples tested. Besides, the amounts of free fatty acids (FFA), raw material, and products were characterized with regard to the content of monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG). It is shown that resins and the immobilized enzyme presented, to a certain extent, satisfactory results, in terms of FFA reduction, while the use of the adsorbent allowed reaching “on spec” biodiesel. It was observed that the water content dramatically affected the quality of the final product, which severely hindered one from reaching lower FFA contents. Integration of resins together with silicate adsorbent seems ...

Vegetable re-esterified oils in diets for rainbow trout: Effects on fatty acid digestibility

The present study aimed at determining the effect of re-esterified oils with different monoacylglycerol (MAG) content, produced from two different vegetable sources with different degrees of saturation, palm and rapeseed, on fatty acid digestibility in rainbow trout. Re-esterified oils were obtained from a chemical esterification process using acid oils (free fatty acids (FFA)-rich by-products from the refining of vegetable oils) and glycerol (by-product of biodiesel production). This process, which produces the formation of triacylglycerols (TAG), reduces the content of FFA present in the acid oil and generates a redistribution of the fatty acids in the glycerol molecule. This redistribution could increase the amount of saturated fatty acids (SFA) located at the sn-2 position of acylglycerols. Moreover, it allows obtaining fats with a certain proportion of MAG, known for being good emulsifiers. Therefore, a higher nutritive value of re-esterified oils than that of acid oils might be expected. A 21-day feeding trial where triplicate groups of rainbow trout were fed nine experimental diets formulated to contain a 21% of different experimental oils was carried out. For each source, four different types of oil were used: native, re-esterified low in MAG, re-esterified high in MAG and acid. A commercial fish oil was used for the control diet. Although re-esterified oils had better apparent digestibility coefficients (ADC) of SFA than their corresponding acid oil diets, no improvement in SFA digestibility was observed in rainbow trout fed re-esterified oils diets compared to those fed native oil diets, not even when a high content of MAG was present. Although this improvement did not occur, both palm and rapeseed re-esterified oils could be incorporated as a fat source in diets for rainbow trout without negatively affecting fatty acid digestibility values. The study concluded that fatty acid digestibility in the experimental oils was more affected by their degree of saturation than by their positional distribution and lipid class composition of the oils.

Surface-active mono- and diacylglycerols obtaining by amidation of linseed oil

Досліджено кінетику амідування лляної олії діетилентриаміном при температурах 413К – 453 К та різних мольних співвідношеннях. Показано, що при цьому утворюється багатокомпонентна суміш, до складу якої входять поверхнево-активні речовини: моноацилгліцерини та діацилгліцерини. За експериментальними даними побудовано кінетичні залежності утворення та витрачання компонентів реакційної маси. Розраховано константи швидкості реакції амідування триацилгліцеринів лляної олії

Synthesis of monoacylglycerol containing pinolenic acid via stepwise esterification using a cold active lipase

High purity monoacylglycerol (MAG) containing pinolenic acid was synthesized via stepwise esterification of glycerol and fatty acids from pine nut oil using a cold active lipase from Penicillium camembertii as a biocatalyst. Effects of temperature, molar ratio, water content, enzyme loading, and vacuum on the synthesis of MAG by lipase-catalyzed esterification of glycerol and fatty acid from pine nut oil were investigated. Diacylglycerol (DAG) as well as MAG increased significantly when temperature was increased from 20 to 40 °C. At a molar ratio of 1:1, MAG content decreased because of the significant increase in DAG content. Water has a profound influence on both MAG and DAG content through the entire course of reaction. The reaction rate increased significantly as enzyme loading increased up to 600 units. Vacuum was an effective method to reduce DAG content. The optimum temperature, molar ratio, water content, enzyme loading, vacuum, and reaction time were 20 °C, 1:5 (fatty acid to glycerol), 2%, 600 units, 5 torr, and 24 h, respectively. MAG content further increased via lipase-catalyzed second step esterification at subzero temperature. P. camembertii lipase exhibited esterification activity up to -30 °C.

A study of the high pressure phase transition of diacylglycerol oil by means of light transmission and scattering

A sample of diacylglycerol (DAG) oil, being a mixture of DAGs and triacylglycerols with a ratio of 82% and 18%, respectively, and with a vestigial content of monoacylglycerols and free fatty acids, has been researched in high pressure conditions. As a result of dynamically applied pressure, a discontinuous (first-order) phase transition of the DAG sample has been observed. After the threshold value of the pressure for the phase change was determined, a number of further measurements were performed. The aim of the measurements was to pressurise the DAG sample with different rates of compression. During the measurements, the following parameters were recorded: the intensities of beams both transmitted and scattered at the angle of 90°, and the temperature of the sample. The obtained data may prove useful for an introductory description of the phase change kinetics induced by dynamically applied pressure.

Enzymatic Production of Monoacylglycerols (MAG) and Diacylglycerols (DAG) from Fish Oil in a Solvent‐Free System

AbstractMono‐ (MAG) and diacylglycerols (DAG) are of nutritional interest. MAG and DAG containing eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids were produced in a solvent‐free system via glycerolysis of menhaden oil catalyzed by Novozym 435. The effect of the molar ratio of glycerol to oil, enzyme concentration, and reaction temperature on MAG and DAG production was assessed. The optimal temperature was in the range of 55–70 °C for production of both acylglycerols. The increase in the substrates molar ratio led to a decrease in MAG and DAG content. The enzyme concentration was fixed at the lowest level evaluated (5%, by weight of substrates). High content of MAG (25% by weight) and DAG (41% by weight) containing, respectively, 12.46% EPA and 11.16% DHA, and 14.57% EPA and 13.70% DHA, were produced after 24 h at 70 °C, with 5% of lipase (by weight of substrate) and a glycerol‐to‐oil molar ratio of 1:1. For this reaction, a molar triacylglycerol (TAG) conversion of about 60% was achieved at equilibrium (10 h).

Leishmanicidal effects of piperine, its derivatives, and analogues on Leishmania amazonensis

Leishmaniasis is a tropical disease caused by protozoan parasites of the genus Leishmania which affects 12 million people worldwide. The discovery of drugs for the treatment of leishmaniasis is a pressing concern in global health programs. The aim of this study aim was to evaluate the leishmanicidal effect of piperine and its derivatives/analogues on Leishmania amazonensis. Our results showed that piperine and phenylamide are active against promastigotes and amastigotes in infected macrophages. Both drugs induced mitochondrial swelling, loose kinetoplast DNA, and led to loss of mitochondrial membrane potential. The promastigote cell cycle was also affected with an increase in the G1 phase cells and a decrease in the S-phase cells, respectively, after piperine and phenylamide treatment. Lipid analysis of promastigotes showed that piperine reduced triglyceride, diacylglycerol, and monoacylglycerol contents, whereas phenylamide only reduced diacylglycerol levels. Both drugs were deemed non toxic to macrophages at 50 μM as assessed by XTT (sodium 2,3,-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)-carbonyl]-2H-tetrazolium inner salt), Trypan blue exclusion, and phagocytosis assays, whereas low toxicity was noted at concentrations higher than 150 μM. None of the drugs induced nitric oxide (NO) production. By contrast, piperine reduced NO production in activated macrophages. The isobologram analysis showed that piperine and phenylamide acted synergistically on the parasites suggesting that they affect different target mechanisms. These results indicate that piperine and its phenylamide analogue are candidates for development of drugs for cutaneous leishmaniasis treatment.

Process Development of Continuous Glycerolysis in an Immobilized Enzyme-Packed Reactor for Industrial Monoacylglycerol Production

Continuous and easily operated glycerolysis was studied in different lipase-packed columns to evaluate the most potential process set-ups for industrial monoacylglycerol (MAG) production. Practical design-related issues such as enzyme-filling degree, required reaction time, mass transfer investigations, and capacity and stability of the enzyme were evaluated. A commercially available immobilized Candida antarctica lipase B was used to catalyze the glycerolysis reaction between glycerol and sunflower oil dissolved in a binary tert-butanol: tert-pentanol medium. Considering easy handling of the enzyme and measured expansion when wetted with a reaction mixture, a filling degree of 52 vol % dry enzymes particles per column volume seemed appropriate. Twenty minutes was required to reach equilibrium conditions with a MAG content of 50-55 wt %. Only insignificant indications of mass transfer limitations were observed. Hence, the commercial lipase seemed adequate to use in its available particle size distribution ranging from 300 to 900 microm. A column length-to-diameter ratio of less than 25 did not interfere with the transfer of the fluid mixture through the column. Under the tested conditions, the enzyme could be active for approximately 92 days before enzyme renewal was needed. This corresponds to a very high enzyme capacity with approximately 2000 L pure MAG produced per kg enzyme.